Even if they did, won’t they get a lot of false positives because of a large amount of it being sprayed hemp buds that are legal as hemp? Also, I know a lot of dispensaries get their stock like vape pens and such delivered this way already. How does that all work?
Why would there be grounds for a lawsuit?
Using their services subjects you to their terms of services…. Which subjects you to their policies on searches and such like…
Of which there’s plenty of things shielding them from exactly this kind of accident.
Iirc, the USPS can’t unilaterally search your letters or packages because, as a government institution, it would be a major violation of the 4th amendment- even postal inspectors need to get a warrant to open a letter or package that’s not expressly addressed to them if it was in the care of the USPS. I think the only exception is when it’s an ‘Operation Santa’ letter, and there are regulations in place for how those get handled to protect the privacy of the sender.
The private parcel and package companies probably don’t have to abide by the same restrictions because they’re not government owned and operated.
There’s also an exception if they can’t read the delivery address; they have the authority to open the package to try to determine delivery address. So make sure your label can get a little wet and still be readable.